This disclosure relates to downhole treatment compositions containing rare earth-containing compounds and methods of using such compositions in downhole cementing and drilling operations.
Downhole treatment compositions are used for various purposes such as for drilling, cementing, and fluid displacement. Density or mass per unit volume is often a critical property differentiating the effectiveness of various treatment compositions in achieving various functions. For example, density can contribute to the stability of the borehole by increasing the pressure exerted by the drilling fluid onto the surface of the formation. Similarly under these circumstances, controlling the density of cement slurry is important to maintain proper well control through hydrostatic head of the cement column. The hydrostatic head prevents the pressurized fluids in the reservoir from producing uncontrollably into the well. Weighting agents such as barite, calcite, and hematite have been used in the past to adjust the density of drilling fluids and cement slurries. In view of the extensive use of weighting agents in downhole applications, the art would be receptive to cost effective alternative materials. It would be a further advantage if the alternative weighting agents can impart additional mechanical or chemical benefits to the treatment compositions.